Field of the Invention
The present invention relates to modules or boxes for storing lengths of optical fibers, and particularly to modules arranged to enable fibers that are stored or routed to the modules to connect to one another inside the modules.
Discussion of the Known Art
A method and materials for installing a bundle of optical fibers associated with a network through a hallway inside a multi-dwelling unit (MDU) building so that living units along the hallway can connect to the network, are offered by OFS Fitel, LLC under the registered mark InvisiLight®. See U.S. Pub. No. 2016/0097911 (Apr. 7, 2016), and U.S. Pat. No. 8,906,178 (Dec. 9, 2014), both of which are incorporated by reference.
Specifically, a covered bundle of network fibers is bonded to a wall or other supporting surface in the hallway via a commercially available adhesive, usually at or near the ceiling over a predefined installation path. The bundle cover is cut open at locations that correspond to each living unit to which one of the fibers has been assigned. At each location, a length of the assigned fiber is retrieved through the cover opening, and stored in a point-of-entry (POE) module that is often mounted, e.g., over an entrance door of the associated living unit. The stored fiber is terminated in an optical connector which in turn is connected to one of two ports of a connector adapter inside the module. Occupants of the living unit can access the assigned network fiber by routing a drop fiber from inside the unit through the hallway wall and into the module, terminating the drop fiber in a connector, and connecting the drop fiber to the other port of the adapter inside the module.
POE fiber storage modules for use in the mentioned InvisiLight procedure are currently available from OFS Fitel, LLC, with connector adapters, as Part No. 301107454 (SCA adapter) and Part No. 301107447 (LCA adapter). The '454 module is illustrated herein in FIGS. 1 and 2. Fiber storage modules for use in fiber-to-the-home (FTTH) and fiber-to-the business (FTTB) installations other than InvisiLight are also commercially available. See, e.g., U.S. Pubs. No. 2016/0033733 (Feb. 4, 2016); No. 2012/0294580 (Nov. 22, 2012); and No. 2015/0147061 (May 28, 2015), all of which are incorporated by reference.
The POE fiber storage module 10 shown in FIGS. 1 and 2 includes a generally rectangular base 12 and a cover 14. The cover 14 is dimensioned and configured to snap or otherwise fasten securely onto the base 12 to enclose and store lengths of optical fibers when routed and retained over the area of the base, and a connector adapter 16 mounted on the base. Both the base 12 and the cover 14 are preferably formed of a non-flammable plastics material such as, e.g., polypropylene to meet all applicable building codes.
In the module 10, the adapter 16 is inserted between a pair of opposed tabs or guides 18, 20 that project upward from the base 12 to form a bracket or slot 22 within which the adapter 16 is mounted at a fixed position midway between the short side edges 12a, 12b of the base. In FIG. 1, the adapter 16 has a generally rectangular solid shape with a long axis A, and first and second ports 17a, 17b. Vertical flanges 16a, 16b project from opposite side walls of the adapter 16, intermediate the first and the second ports 17a, 17b. The tabs 18, 20 on the base 12 form corresponding guideways 18a, 20a on opposite sides of the bracket 22, for receiving and seating the flanges 16a, 16b at the sides of the adapter 16 when the adapter is inserted in the bracket 22. Typical dimensions of the module 10 are, approximately, a length L of 5.25 inches, a height H of 2.5 inches, and a depth D of 0.770 inch.
In use, an opening is formed in the hallway wall to provide a passage for an end length of a drop fiber that originates from and is terminated inside the living unit associated with the module 10. The module is mounted on the hallway wall so that the passage for the drop fiber coincides with an opening 24 in the module base 12. The fiber bundle installed along the hallway is routed to pass through the module 10, between the short side edges 12a, 12b of the module base 12 and next to an upper edge 12c of the base.
A network fiber assigned to the living unit is retrieved from the fiber bundle, through an opening that is cut in the bundle cover between the side edges 12a, 12b of the base. The fiber is then preferably inserted through a thin plastics sleeve or tube to avoid damage while being handled, and dressed about a series of retaining fingers or tabs 28 that project upward from the base 12. The free end of the fiber is terminated in an optical connector and connected to one of the connecter ports 17a, 17b at one end of the adapter 16. The module cover 14 is then fastened to the base 12, and the cover 14 is opened when occupants of the living unit subscribe to network service and need to connect to the stored network fiber. The drop fiber is then routed from inside the living unit, through the passage in the hallway wall and the opening 24 in the module base 12, terminated, and connected to the other one of the ports 17b, 17a at the opposite end of the adapter 16.
Because the present dimensions of the module 10 can sometimes create a negative impact visually when a number of the modules are installed along a hallway wall and seen all at once, a need for a smaller size module has arisen. Reducing the overall size of the module 10 could, however, make it difficult to dress or manage a fiber properly for storage inside the module without bending the fiber beyond a critical degree which damages or impairs the performance of the fiber. That is, if the present dimensions of the module 10 are simply reduced, it may not always be possible to connect a fiber routed inside the module for storage to a port of the adapter 16, without having to bend the fiber beyond a specified critical limit. See FIGS. 5 and 7, and related description below.